IQ Percentile and Rarity Chart

These are IQs, their percentiles, and rarity on a 15 SD (e.g.
Wechsler) and 16 SD (e.g. Stanford-Binet) scale. They were calculated
using the NORMDIST function in Excel. The number of decimal places
for the rarity was varied in the hope it might be useful. You can see
why presently nobody should be able to get a deviation IQ higher than 195
(or 201 on the 16 SD scale). There are not enough people in the world
to 'beat'. Note that rarities given are of people that have a certain IQ or higher. Some people might find it more useful to know the rarity of people that have a certain IQ or lower. In that case use this example as a guide: If you want to know how many people
have IQs of 84 or lower, look at the rarity of people that have an IQ of 116
or higher. (100 - 84 = 16. 100 + 16 = 116).